<!DOCTYPE html>
<html lang="en" ng-app="main">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>

    </style>
    <script src="angular.min.js"></script>
    <script>
        let mod = angular.module('main',[]);
        mod.controller('con1',function ($scope,$interval) {
            $scope.a = 12
	        $interval(function () {
		        $scope.a++;
	        },1000)
        })
    </script>
</head>
<body ng-controller="con1">
a:{{a}}
</body>
<script>

</script>
</html>